U.S. patent application number 14/927370 was filed with the patent office on 2016-05-05 for working machine.
This patent application is currently assigned to J. C. Bamford Excavators Limited. The applicant listed for this patent is J. C. Bamford Excavators Limited. Invention is credited to John Griffin, Peter Jowett, Jonathan Lyle.
Application Number | 20160122971 14/927370 |
Document ID | / |
Family ID | 52103601 |
Filed Date | 2016-05-05 |
United States Patent
Application |
20160122971 |
Kind Code |
A1 |
Lyle; Jonathan ; et
al. |
May 5, 2016 |
WORKING MACHINE
Abstract
A working machine comprising a ground engaging structure and an
undercarriage connected to the ground engaging structure. A
superstructure is rotatably mounted to the undercarriage so as to
be rotatable relative to the undercarriage about a first generally
upright axis, an operator's cab is rotatably mounted on the
superstructure so as to be rotatable relative to the superstructure
about a second generally upright axis, and a working arm is
rotatably mounted to the superstructure so as to be moveable up and
down about a generally horizontal axis. A drive arrangement is
provided for driving the ground engaging structure to propel the
working machine. The drive arrangement includes an engine and
transmission that are housed within the undercarriage, and a
majority of the engine is positioned below a level coincident with
a lower extent of the superstructure.
Inventors: |
Lyle; Jonathan; (Uttoxeter,
GB) ; Griffin; John; (Uttoxeter, GB) ; Jowett;
Peter; (Uttoxeter, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
J. C. Bamford Excavators Limited |
Uttoxeter |
|
GB |
|
|
Assignee: |
J. C. Bamford Excavators
Limited
Uttoxeter
GB
|
Family ID: |
52103601 |
Appl. No.: |
14/927370 |
Filed: |
October 29, 2015 |
Current U.S.
Class: |
414/687 |
Current CPC
Class: |
E02F 9/18 20130101; E02F
9/08 20130101; E02F 9/02 20130101; E02F 9/085 20130101; E02F 3/325
20130101; E02F 9/0883 20130101; E02F 9/166 20130101; E02F 9/0866
20130101 |
International
Class: |
E02F 9/08 20060101
E02F009/08; E02F 9/18 20060101 E02F009/18; E02F 9/02 20060101
E02F009/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 29, 2014 |
GB |
1419273.6 |
Claims
1. A working machine comprising: a ground engaging structure; an
undercarriage connected to the ground engaging structure; a
superstructure rotatably mounted to the undercarriage so as to be
rotatable relative to the undercarriage about a first generally
upright axis; an operator's cab rotatably mounted on the
superstructure so as to be rotatable relative to the superstructure
about a second generally upright axis; a working arm rotatably
mounted to the superstructure so as to be moveable up and down
about a generally horizontal axis; and a drive arrangement for
moving the ground engaging structure to propel the working machine,
the drive arrangement including a prime mover and transmission; and
wherein the prime mover and transmission are housed within the
undercarriage, and the prime mover is positioned below a level
coincident with a lower extent of the superstructure.
2. The working machine according to claim 1, wherein the working
arm is rotatably mounted to the superstructure so as to be
rotatable relative to the superstructure about a third generally
upright axis.
3. The working machine according to claim 1, wherein the ground
engaging structure includes a front and rear axle each having a
pair of wheels mounted thereto preferably wherein a majority of the
prime mover is positioned below a level coincident with an upper
extent of the wheels.
4. The working machine according to claim 1, wherein the prime
mover is mounted in a transverse direction to a fore-aft direction
of the working machine.
5. The working machine according to claim 4, wherein the prime
mover is mounted substantially perpendicular to the fore-aft
direction of the working machine.
6. The working machine according to claim 1, wherein the prime
mover is a reciprocating engine including pistons and the engine is
mounted such that the pistons have an upright orientation.
7. The working machine according to claim 1, wherein a heat
exchanger and cooling fan are mounted adjacent the prime mover and
arranged such that an axis of rotation of the fan is substantially
parallel to a fore-aft direction of the working machine.
8. The working machine according to claim 1, wherein the working
machine comprises a fuel tank positioned on one side of an axis
extending in the fore-aft direction of the working machine and the
prime mover is positioned on the other side of an axis extending in
the fore-aft direction of the working machine.
9. The working machine according to claim 1, wherein the working
machine comprises a hydraulic fluid tank positioned on one side of
an axis extending in a fore-aft direction of the working machine
and the engine is positioned on the other side of the axis
extending in the fore-aft direction of the working machine.
10. The working machine according to claim 1, wherein the cab is
positioned substantially centrally to the superstructure.
11. The working machine according to claim 1, wherein the second
upright axis about which the superstructure is rotated is
substantially central to the undercarriage.
12. The working machine according to claim 1, wherein a counter
weight is mounted to the superstructure in a position opposite the
working arm.
13. The working machine according to claim 12, wherein the counter
weight is curved and a portion of the cab is curved, and wherein
the curve of the counter weight follows the curve of the cab.
14. The working machine according to claim 1, wherein the
superstructure is dimensioned to be longer in length than width,
the length and width being defined such that when the working
machine is driving along a road the length of the superstructure is
in a fore-aft direction.
15. The working machine according to claim 14, wherein the working
arm is mounted to the superstructure at a position that is at one
end of the superstructure in a length direction and central to the
superstructure in a width direction.
16. The working machine according to claim 1, wherein the
superstructure can rotate relative to the undercarriage by at least
180.degree..
17. The working machine according to claim 1, wherein the cab can
rotate relative to the superstructure by at least 180.degree..
18. The working machine according to claim 1, wherein the rotary
connection between the superstructure and the undercarriage
includes a rotary joint arrangement configured to permit electrical
signals and/or hydraulic fluid to be routed to the superstructure
independently of the position of the superstructure relative to the
undercarriage.
19. The working machine according to claim 1, wherein the working
machine is at least a compact tail swing excavator, preferably
wherein the working machine is a zero tail swing excavator.
20. The working machine according to claim 1, wherein the axis of
rotation of the cab with respect to the superstructure is
coincident with the axis of rotation of the superstructure with
respect to the undercarriage.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a working machine.
BACKGROUND OF THE INVENTION
[0002] Various types of working machines are known. Such machines
are used typically for soil-shifting operations (e.g. trenching,
grading, and loading) and materials handling (e.g. depositing
aggregate in trenches, lifting materials and placing them on an
elevated platform).
[0003] Such machines are typically manufactured from a set of
subassemblies designed specifically for one type of machine,
although certain components such as engines, gearboxes, and
hydraulic pumps may be shared across different machine types.
[0004] Examples of known machines include the following:
[0005] Slew excavators comprise a superstructure rotatable in an
unlimited fashion relative to an undercarriage. The superstructure
includes a working arm arrangement for manipulating an attachment,
such as a bucket, to perform working operations of the type listed
above, a prime mover, such as a diesel IC engine, a hydraulic pump,
and an operator cab. The prime mover drives the hydraulic pump, in
order to provide pressurized fluid to operate the working arm
arrangement, and also to power one or more hydraulic motors located
in the undercarriage that are used to selectively drive either two
endless tracks or four wheels (or eight wheels in a dual wheel
configuration) for propelling the excavator.
[0006] A slew ring rotatably connects the superstructure and
undercarriage, and a central rotary joint arrangement enables
hydraulic fluid to pass from the pump in the superstructure to the
hydraulic motor, and return to the superstructure, irrespective of
the relative positions of the superstructure and undercarriage. If
the slew excavator uses tracks for propulsion, steering is effected
by differentially driving the tracks on opposing sides of the
undercarriage. If the slew excavator uses wheels for propulsion, a
steering arrangement is used for either two or four wheels, and
separate hydraulic control is required for this in the
undercarriage.
[0007] Slew excavators are available in a wide range of sizes.
Micro, mini and midi excavators span an operating weight range from
around 750 kg up to around 12,000 kg and are notable for typically
having a working arm arrangement that is capable of pivoting about
a substantially vertical axis relative to the superstructure by
using a "kingpost" interface to the superstructure. Generally, mini
and midi excavators have a weight of above around 1,200 kg. Large
excavators, whose operating weight exceeds around 12,000 kg are
often referred to as `A frame` excavators and typically have a
working arm arrangement that is fixed about a vertical axis, and
can therefore only slew together with the superstructure. This is a
function of the fact that the smaller excavators are expected to
operate in more confined spaces and the ability to slew about two
mutually offset axes in order to, for example, trench close to an
obstacle such as a wall is therefore more desirable for micro, mini
and midi excavators.
[0008] The working arm arrangement generally includes a boom
pivotally connected to a dipper. There are several types of booms
available including: a triple articulated boom which has two
pivotally connected sections; and a mono boom that is often made
from a single generally curved structure. A dipper is pivotally
connected to the boom and a mount for an attachment, e.g. a bucket,
is provided on the dipper. Hydraulic cylinders are provided to move
the boom, dipper and mount relative to each other so as to perform
a desired working operation.
[0009] Tracked excavators are not able to travel under their own
propulsion for significant distances due to a low maximum speed and
the damage their metal tracks cause to paved roads. However their
tracks enhance the stability of the excavator. Wheeled excavators
are capable of "roading" at higher speeds (typically up to 40 kph),
and without appreciably damaging paved road surfaces. However, the
working arm assembly inevitably extends forward of the
superstructure during roading, which can impair ride quality, and
forward visibility. When performing working operations the
pneumatic tires provide a less stable platform than tracks, so
additional stabilizer legs can be deployed for stability.
[0010] Since the prime mover, hydraulic pump, hydraulic reservoir
etc. are located in the superstructure, the center of gravity of
all types of slew excavator is relatively high. Whilst these
components can be positioned to act as a counterbalance to forces
induced during working operations, packaging constraints may force
such positioning to be sub-optimal, and may also restrict
sight-lines over the rear of the machine, for example.
[0011] Excavators are generally used for operations such as
digging. However, if it is desired to perform an operation such as
loading, an alternative type of machine must be used. Machines
capable of loading operations are known and have various formats.
In one format, commonly referred to as a "telescopic handler" or
"telehandler", the superstructure and undercarriage are fixed
relative to each other and a central working arm in the form of a
two or more part telescopic boom extends fore-aft of the machine.
The boom pivots about a horizontal axis towards the aft end of the
machine, an attachment is releasably mounted to a fore end of the
boom, and is pivotable about a second distinct horizontal axis.
Commonly used attachments include pallet forks and shovels.
Telehandlers may be used for general loading operations (e.g.
transferring aggregate from a storage pile to a required location
on a construction site) and lifting operations, such as lifting
building materials on to an elevated platform.
[0012] Telehandlers typically have four wheels on two axles for
propulsion, with one or both axles being steerable and driven. A
prime mover (typically a diesel IC engine) may be located in a pod
offset to one side of the machine between front and rear wheels and
is connected to the wheels by a hydrostatic or mechanical
transmission. An operator cab is often located on the other side of
the boom to the prime mover, and is relatively low between the
wheels. Depending upon its intended application, the machine may be
provided with deployable stabilizer legs.
[0013] A subset of telehanders mount the cab and boom on a
rotatable superstructure in order to combine lifting with slewing
operations, at the expense of additional weight and greater height.
As these machines are used principally for lifting, instead of
loading, they have a longer wheelbase than conventional
telehandlers to accommodate a longer boom, impacting
maneuverability. Further, as sight-lines towards the ground close
to the machine are less critical for lifting than for excavating,
these are consequently quite poor.
[0014] It is further desirable that working machines become more
efficient in operation, in terms of the amount of working
operations undertaken for a given amount of fuel used. This may be
a function of the fuel efficiency of the prime mover, transmission,
driveline and hydraulic system, as well as being due to secondary
factors such as poor visibility meaning that an operator needs to
reposition the working machine unnecessarily frequently so as to
view the working operation, or carrying out an operation much more
slowly thereby compromising efficiency.
SUMMARY OF THE INVENTION
[0015] The present invention aims to alleviate one or more of the
problems associated with working machines of the prior art.
[0016] A first aspect of the invention provides a working machine
comprising a ground engaging structure; an undercarriage connected
to the ground engaging structure; a superstructure rotatably
mounted to the undercarriage so as to be rotatable relative to the
undercarriage about a first generally upright axis; an operator's
cab rotatably mounted on the superstructure so as to be rotatable
relative to the superstructure about a second generally upright
axis; a working arm rotatably mounted to the superstructure so as
to be moveable up and down about a generally horizontal axis; and a
drive arrangement for moving the ground engaging structure to
propel the working machine, the drive arrangement including a prime
mover and transmission; and wherein the prime mover and
transmission are housed within the undercarriage, and the prime
mover is positioned below a level coincident with a lower extent of
the superstructure.
[0017] Advantageously, the cab and superstructure of the present
invention can be rotated relative to each other for optimized
working in confined working spaces and improved visibility. For
example, when the working machine is driven on the road, the cab
and superstructure can be rotated relative to each other so as to
position the working arm to the rear of the working machine to give
an operator an improved view of the road ahead.
[0018] Visibility is further improved by housing the prime mover
and transmission within the undercarriage and positioning the
majority of the prime mover below a level coincident with an upper
extent of the wheels. Often in conventional working machines the
prime mover is housed in the superstructure, but this creates a
barrier to sight for an operator of the working machine. Moving the
prime mover to a lower position on the working machine moves the or
part of the prime mover away from the line of sight of an operator.
The working arm may comprise a mount for mounting an attachment,
e.g. a bucket.
[0019] In one embodiment, the working arm is rotatably mounted to
the superstructure so as to be rotatable relative to the
superstructure about a third generally upright axis.
[0020] Provision of a working arm rotatable relative to the
superstructure about a third generally upright axis advantageously
further improves the versatility of the working machine, and the
visibility for a user during a wide range of operations. For
example, when the machine is excavating near a barrier, e.g. a
wall, the cab, superstructure and working arm can be rotated
relative to each other such that the working arm is to the front of
the machine but offset to one side, permitting digging close to the
wall and the cab can be rotated towards the region to be dug to
improve visibility of the excavating operation
[0021] In one embodiment, the ground engaging structure includes a
front and rear axle each having a pair of wheels mounted
thereto.
[0022] In one embodiment, a majority of the prime mover is
positioned below a level coincident with an upper extent of the
wheels.
[0023] In one embodiment, the prime mover is positioned between the
front and rear axles.
[0024] Such positioning advantageously further improves visibility
of an operator and the compactness of the working machine.
[0025] In one embodiment, the prime mover is mounted in a
transverse direction to a fore-aft direction of the working
machine.
[0026] In one embodiment, the prime mover is mounted substantially
perpendicular to the fore-aft direction of the working machine. The
prime mover may be an engine, for example a reciprocating engine
e.g. a diesel IC engine.
[0027] In one embodiment, the prime mover is a reciprocating engine
including pistons and the engine is mounted such that the pistons
have an upright orientation.
[0028] In one embodiment, a heat exchanger and cooling fan are
mounted adjacent the prime mover and arranged such that an axis of
rotation of the fan is substantially parallel to a fore-aft
direction of the working machine.
[0029] In one embodiment, the working machine comprises a fuel tank
positioned on one side of an axis extending in the fore-aft
direction of the working machine and the prime mover is positioned
on the other side of an axis extending in the fore-aft direction of
the working machine.
[0030] In one embodiment, the working machine comprises a hydraulic
fluid tank positioned on one side of an axis extending in a
fore-aft direction of the working machine and the engine is
positioned on the other side of the axis extending in the fore-aft
direction of the working machine.
[0031] In one embodiment, the cab is positioned substantially
centrally to the superstructure.
[0032] In one embodiment, the second upright axis about which the
superstructure is rotated is substantially central to the
undercarriage.
[0033] In one embodiment, a counter weight is mounted to the
superstructure in a position opposite the working arm.
[0034] In one embodiment, the counter weight is curved and a
portion of the cab is curved, and wherein the curve of the counter
weight follows the curve of the cab.
[0035] Such a configuration is advantageous for providing a more
compact superstructure. For example, a front and a rear of the cab
may be curved.
[0036] In one embodiment, the working arm has a boom and a dipper
pivotally connected to the boom.
[0037] In one embodiment, one or more hydraulic cylinders are
configured to pivot the dipper relative to the boom.
[0038] Advantageously the boom may comprise at least two sections
pivotally connected (e.g. the boom is a triple articulated boom).
One or more hydraulic cylinders may be configured to rotate one
section of the boom relative to another section of the boom.
[0039] In one embodiment, the working machine weighs between about
1200 kg and 12000 kg. For example, the working machine may be a
mini or a midi excavator.
[0040] In one embodiment, the working arm is mounted to the
superstructure using a kingpost arrangement.
[0041] In one embodiment, a hydraulic cylinder is used to rotate
the working arm relative to the superstructure about the third
generally upright axis.
[0042] In one embodiment, the transmission comprises a hydraulic
pump and a hydraulic motor.
[0043] In one embodiment, the hydraulic pump supplies fluid to the
hydraulic cylinder to actuate rotation of the working arm.
[0044] In one embodiment, the hydraulic pump supplies fluid to the
one or more hydraulic cylinders to rotate the dipper relative to
the boom.
[0045] In one embodiment, the superstructure is dimensioned to be
longer in length than width, the length and width being defined
such that when the working machine is driving along a road the
length of the superstructure is in a fore-aft direction.
[0046] In one embodiment, the working arm is mounted to the
superstructure at a position that is at one end of the
superstructure in a length direction and central to the
superstructure in a width direction. The undercarriage may be
longer in a fore-aft direction than the superstructure.
[0047] In one embodiment, the superstructure can rotate relative to
the undercarriage by at least 180.degree..
[0048] In one embodiment, the cab can rotate relative to the
superstructure by at least 180.degree..
[0049] In one embodiment, the superstructure is rotatable relative
to the undercarriage and/or the cab is rotatable relative to the
superstructure using an electric motor.
[0050] In one embodiment, the superstructure is rotatable relative
to the undercarriage and/or the cab is rotatable relative to the
superstructure using the hydraulic motor.
[0051] In one embodiment, the rotary connection between the
superstructure and the undercarriage includes a rotary joint
arrangement configured to permit electrical signals and/or
hydraulic fluid to be routed to the superstructure independently of
the position of the superstructure relative to the
undercarriage.
[0052] In one embodiment, the rotary connection between the
superstructure and the cab includes a mechanism for routing hoses
and/or cables from the superstructure to the cab, the mechanism
being configured to permit hoses and/or cables to be wound or
unwound to account for the position of the cab relative to the
superstructure.
[0053] In one embodiment, the working machine is configured for
four wheel drive.
[0054] In one embodiment, the front and rear axles are configured
for at least two wheel steer. For example, the front and rear axles
may be configured for two or four wheel steer.
[0055] The cab may have a width of between one third and two thirds
of the distance between an outboard side of each of the wheels of
the pair of wheels mounted to the front axle. The cab may have a
width of between one third and one half of the distance between an
outboard side of each of the wheels of the pair of wheels mounted
to the front axle. The superstructure may have a width
substantially equal to or less than the width of the undercarriage.
The superstructure may have a length substantially equal to one
half to three quarters of the length of the undercarriage.
[0056] In one embodiment, the line of sight angle over the right
hand rear corner of the machine for an operator having a height of
185 cm is at least 30.degree. below the horizontal, more preferably
at least 45.degree. below the horizontal.
[0057] In one embodiment, the working machine is at least a compact
tail swing excavator, preferably wherein the working machine is a
zero tail swing excavator.
[0058] In one embodiment, the axis of rotation of the cab with
respect to the superstructure is coincident with the axis of
rotation of the superstructure with respect to the
undercarriage.
[0059] In one embodiment, the axis of rotation of the cab with
respect to the superstructure is offset from the axis of ration of
the superstructure with respect to the undercarriage.
[0060] In one embodiment, the working machine comprises stabilizing
feet that are extendable to engage with the ground.
[0061] In one embodiment, the working machine comprises a dozer
blade.
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] Embodiments of the invention will now be described with
reference to the accompanying drawings, in which:
[0063] FIG. 1 is a side view of a working machine according to an
embodiment of the present invention in a straight dig position;
[0064] FIG. 2 is a plan view of the machine of FIG. 1;
[0065] FIG. 3 is a front view of the machine of FIG. 1;
[0066] FIG. 4 is a plan view of an undercarriage portion of the
machine of FIG. 1;
[0067] FIG. 5 is a side view of the machine of FIG. 1 in an offset
dig position;
[0068] FIG. 6 is a front view of the machine of FIG. 5;
[0069] FIG. 7 is a plan view of the machine of FIG. 5;
[0070] FIG. 8 is a side view of the working machine of FIG. 1 in a
roading position;
[0071] FIG. 9 is a plan view of the machine of FIG. 8;
[0072] FIG. 10 is a front view of the machine of FIG. 8; and
[0073] FIG. 11 is a rear view of the machine of FIG. 8.
DETAILED DESCRIPTION OF EMBODIMENT(S)
General Format
[0074] With reference to FIGS. 1 to 3, there is illustrated in
somewhat simplified form a working machine 10 according to an
embodiment of the present invention. In the present embodiment, the
working machine may be considered to be a midi excavator (operating
weight between approx. 6 and 12 metric tons). In other embodiments
the working machine may be a mini excavator (operating weight
between 1.2 and 6 tons). The machine comprises an undercarriage 12
and a superstructure 14 linked by a slewing mechanism in the form
of a slewing ring 16. The slewing ring 16 permits unrestricted
rotation of the superstructure relative to the undercarriage 12 in
this embodiment. A cab 30 from which an operator can operate the
working machine is rotatably mounted to the superstructure. A
working arm arrangement 40 is also rotatably mounted to the
superstructure and provided for performing material handling
operations.
Undercarriage
[0075] The undercarriage is formed from a pair of spaced parallel
chassis rails 18a and 18b extending fore-aft. The rails provide a
majority of the strength of the undercarriage 12. The undercarriage
is connected to a ground engaging structure, which in this
embodiment includes first and second drive axles 20a and 20b are
mounted to the chassis rails 18a, 18b and wheels rotatably attached
to each axle end. In this embodiment the second drive axle 20b is
fixed with respect to the chassis rails 18a, 18b, whereas the first
drive axle 20a is capable of limited articulation, thereby
permitting the wheels to remain in ground contact, even if the
ground is uneven. The wheels 19a, 19b, 19c, 19d, are typically
provided with off-road pneumatic tires. The wheels connected to
both axles 20a, 20b are steerable via a steering hub 17a, 17b, 17c,
17d. In this embodiment, the wheelbase is 2.65 m, and a typical
range is 2.0 m to 3.5 m.
[0076] For the purposes of the present application, the fore-aft
direction A is defined as a direction substantially parallel to the
general direction of the chassis rails 18a and 18b. A generally
upright direction U is defined as a direction substantially
vertical when the working machine is on level ground. A generally
lateral direction L is defined as a direction that is substantially
horizontal when the working machine is on level ground and is
substantially perpendicular to the fore-aft direction A.
[0077] In this embodiment a dozer blade arrangement 22 is pivotally
secured to one end of the chassis rails 18a and 18b, which may be
raised and lowered by hydraulic cylinders 21 using a known
arrangement, and also act as a stabilizer for the machine, by
lifting the adjacent wheels off the ground when excavating, however
this may not be provided in other embodiments.
[0078] A stabilizer leg arrangement 24 is pivotally mounted to an
opposite end of the chassis rails 18a and 18b, which also may be
raised and lowered by hydraulic cylinders 23 using a known
arrangement, but in other embodiments this may be omitted.
Drive
[0079] Referring now to FIG. 4, contrary to known excavators, the
drive arrangement, including a prime mover and transmission are
housed in the undercarriage 12. In the present embodiment, the
prime mover is a diesel IC engine 64. The engine 64 is mounted to
one side of an axis B extending centrally through the undercarriage
in a fore-aft direction. The engine 64 is mounted transverse to the
axis B, i.e. an axis of rotation R of a crankshaft of the engine is
transverse to the axis B in the fore-aft direction. The engine 64
is further orientated such that the pistons of the engine extend in
the substantially upright direction U.
[0080] A heat exchanger 66 and cooling fan 68 are housed in the
undercarriage adjacent the engine 64. The cooling fan 68 is
orientated such that the axis of rotation Q of the fan extends in a
fore-aft direction A, although it may be oriented differently in
other embodiments.
[0081] A fuel tank 70 providing a fuel supply to the engine 64 is
positioned on an opposite side of the axis B to the engine. A
hydraulic tank 72 is provided adjacent the fuel tank 70 on an
opposite side of the axis B to the engine.
[0082] The engine 64, heat exchanger 66, cooling fan 68, fuel tank
70 and hydraulic tank 72 are all housed in a region between the
axles 20a and 20b. As can be seen in FIG. 1, the engine 64 is
positioned below a level coincident with a lower extent of the
superstructure 14. Indeed the majority of the engine 64, and in
this embodiment the entire engine 64 is positioned below a level Q
coincident with an upper extent of the wheels 19a, 19b, 19c, 19d.
In the present embodiment the majority of the heat exchanger 66,
cooling fan 68, fuel tank 70 and hydraulic tank 72 are below a
level Q coincident with the upper extent of the wheels 19a, 19b,
19c, 19d.
[0083] In the present embodiment the transmission is a hydrostatic
transmission, but in alternative embodiments the transmission may
be mechanical or electrical. The transmission includes a hydraulic
pump 74 and a hydraulic motor 76. The engine 64 is configured to
drive the pump 74, and the pump 74 is configured to supply
hydraulic fluid from the hydraulic fluid tank 72 to the hydraulic
motor 76. The hydraulic motor 76 rotates two drive shafts 78, 80
that rotate the axles 20a, 20b to propel the working machine 10
along the ground, i.e. in the present embodiment the working
machine is four wheel drive. In alternative embodiments the working
machine may be two wheel drive or may be configured to permit an
operator to select two or four wheel drive.
[0084] The pump 74 is positioned adjacent the engine 64 and is
orientated such that an input to the pump from the engine is
axially aligned with an output from the engine to the pump. The
hydraulic motor 76 is positioned such that an axis of rotation of
the hydraulic motor is coincident with the axis B. In the present
embodiment the hydraulic motor 76 is positioned to one side of an
axis C extending centrally through the undercarriage in a lateral
direction L, on an opposite side of the axis C to the hydraulic
pump 74 and engine. That is, in the present embodiment, the
hydraulic motor 76 is positioned towards the dozer blade
arrangement 22, and the engine and hydraulic pump are positioned
towards the stabilizer arrangement 24.
[0085] The hydraulic pump 74 further supplies hydraulic fluid to
the hydraulic cylinders 50, 52, 54, 60, 62 for operating the
working arm arrangement (discussed below) and hydraulic cylinders
21, 23 of the dozer blade and stabilizer arrangement, and a
suitable control valve arrangement is configured to control supply
to the hydraulic cylinders. However, in alternative embodiments
individual pumps may be used for supplying hydraulic fluid to the
motors and the hydraulic cylinders for one or more of the hydraulic
cylinders.
Superstructure
[0086] The superstructure 14 comprises a structural platform 26
mounted on the slewing ring 16. As can be seen in the Figures, the
slew ring 16 is substantially central to the undercarriage 12 in a
fore-aft direction A and a lateral direction L, so as to mount the
superstructure 14 central to the undercarriage. The slew ring 16
permits rotation of the superstructure 14 relative to the
undercarriage about a generally upright axis Z.
[0087] A rotary joint arrangement 85 is provided central to the
slew ring 16 and is configured to provide multiple hydraulic fluid
lines, a return hydraulic fluid line, and an electrical--Controller
Area Network (CAN)--signal line to the superstructure from the
undercarriage, whilst permitting a full 360.degree. rotation of the
superstructure relative to the undercarriage. The configuration of
such a rotary joint arrangement is known in the art.
[0088] The platform 26 mounts a cab 30. The cab houses the
operator's seat and machine controls. The cab is mounted to the
platform via a rotary arrangement 32 that connects electrical
cable(s) and/or hydraulic hose(s) (not shown) between the
superstructure 14 and the cab. A slack is provided in the cables
and/or hydraulic hoses to permit the cables/hoses to be wound or
unwound to allow for rotation of the cab relative to the
superstructure about a generally upright axis Y. Rotation of the
cab 30 relative to the superstructure 14 is limited to 270.degree.
in this embodiment, but may be in a range of 180.degree. to
360.degree.. Limiting rotation to less than 360.degree. permits a
simplified arrangement to be used to route cables and/or hoses to
the cab. Alternatively, the rotary arrangement could be arranged to
permit a full 360.degree. of rotation, e.g. using a rotary joint
arrangement similar to that between the undercarriage and the
superstructure.
[0089] The superstructure 14 is rotated relative to the
undercarriage 12 using a first hydraulic motor 32. The cab 30 is
rotated relative to the superstructure 14 using a second hydraulic
motor (not visible in the drawings) which is situated under the
operator's seat. In alternative embodiments the superstructure
and/or cab may be rotated using an electric motor.
[0090] In this embodiment axes Y and Z are offset, but in other
embodiments may be coincident.
[0091] The platform further mounts a kingpost 28 for a working arm
arrangement 40. The kingpost 28 arrangement is known in the art,
and permits rotation of the working arm about a generally upright
axis X and about a generally lateral axis W.
[0092] The superstructure 14 further comprises a counterweight 34
for the working arm arrangement positioned at an opposite side of
the superstructure to the kingpost 28.
[0093] In the straight dig position shown in FIGS. 1 to 3, the
counterweight 34 is behind the cab 30 to optimize the
counterbalance effect, and in the roading position shown in FIGS. 8
to 11 the counterweight 34 is in front of the cab 30.
[0094] In this embodiment, the counterweight 34 has a curved
profile in a region nearest the cab. The rear 36 of the cab and the
front 38 of the cab each have a curved profile that is
complimentary to the curved profile of the counterweight. The
complimentary curved profiles accommodate rotation of the cab
relative to the superstructure 14 in a particularly compact manner.
The counterweight protrudes upwardly from the platform 26 by a
distance that is 1/4 to 1/3 of the height of the cab 30. Such a
height has been found to have limited impedance on an operator's
line of sight across a range of operating modes. That is, an
operator's line of sight is improved in the straight dig position
shown in FIGS. 1 to 3 when looking over their shoulder and is
equally good on each lateral side of the cab when the operator is
facing forwards.
[0095] In this embodiment the excavator may be considered to be a
compact tail swing (CTS) excavator because the counterweight
extends a minimal amount beyond the footprint of the undercarriage.
In other embodiments, the working machine may be configured on a
zero tail swing (ZTS) excavator where the counterweight does not
project beyond the footprint of the undercarriage in any
position.
Working Arm
[0096] The working arm arrangement 40 of the present embodiment is
an excavator arm arrangement. The working arm arrangement includes
a triple articulated boom 42 pivotally connected to a dipper 44.
The triple articulated boom 42 includes a first section 46
pivotally connected to a second section 48. A hydraulic cylinder 50
is provided to raise and lower the first section 46 of the boom 42
relative to the kingpost 28 about the generally lateral axis W. A
further hydraulic cylinder 52 is provided to pivot the second
section 48 of the boom 42 relative to the first section of the boom
about a generally lateral axis T. A yet further hydraulic cylinder
54 is provided to rotate the dipper 44 relative to the boom 42
about a generally lateral axis S. A mount 56 is provided to
pivotally mount an attachment to the dipper 44, in the present
embodiment the attachment is a bucket 58. A hydraulic cylinder 60
is provided to rotate the attachment relative to the dipper 44.
Alternative boom cylinder arrangements (e.g. twin cylinders) may
however be utilized in other embodiments.
[0097] Shown most clearly in FIG. 2, a yet further hydraulic
cylinder 62 is provided to rotate the working arm arrangement 40
about the generally upright axis X. Using a hydraulic cylinder
arrangement to rotate the working arm arrangement simplifies
manufacture and operation of the working machine 10.
[0098] Provision of a cab 30 rotatable relative to the
superstructure 14, a superstructure rotatable relative to the
undercarriage 12, and a working arm arrangement 40 rotatable
relative to the superstructure permits said components of the
working machine to be rotated relative to each other such that an
operator has improved visibility compared to working machines of a
similar type of the prior art and also to enable the working
machine to work within a confined space.
[0099] Housing the engine in the undercarriage, as opposed to a
more conventional position in the superstructure 14, improves
visibility for a user. Positioning the engine in the undercarriage
instead of, for example the superstructure, and positioning a
majority of the engine below the level Q means that the engine does
not create a barrier or at least a much lesser barrier to the line
of sight of an operator. As a result the line of sight angle
.alpha. (FIG. 1) over the right hand rear corner of the machine for
an operator having a height of 185 cm (a 95th percentile male) when
seated in the operator's seat is at least 30.degree. below the
horizontal, but more typically at least 40.degree. or even up to
50.degree. (compared to around 22.degree. in conventional midi
excavators of this size). This results in a significant reduction
of the ground area around the machine that is obscured by parts of
the superstructure, thereby improving visibility for maneuvering
the machine. In the present embodiment, the drive arrangement has
been arranged to be compactly housed within the undercarriage,
which minimizes the width, length and height of the undercarriage
to further improve visibility for a user.
[0100] As can be seen in the drawings, the present invention
provides a compact working machine, and the position of the engine
and transmission contributes to achieving said compactness.
Referring to FIGS. 1 to 3, it can be seen that the superstructure
14 is approximately 3/4 of the length of the undercarriage 12.
However, the width of the superstructure is substantially equal to
the width of the undercarriage. The cab 30 is approximately 1/2 of
the width of the undercarriage 12, measured at the widest points,
and 3/4 of the length of the superstructure 14, measured at the
longest points. The described dimensions of the working machine
have been found to further improve visibility and also provide a
versatile machine capable of operating in confined spaces.
[0101] The various advantages of the present invention will become
apparent from the following description of the various operating
modes of the working machine.
Straight Dig Operation
[0102] Referring to FIGS. 1 to 3, if an operator would like to
perform a straight dig, the cab 30 is rotated about the upright
axis Y so that an operator is facing a direction generally towards
the dozer blade arrangement 22. The superstructure 14 is rotated
about the upright axis Z so that the working arm arrangement 40 is
only slightly offset from the axis B and so that the counterweight
34 is behind the cab and the operator can see down the side of the
working arm into e.g. a trench being excavated. The hydraulic
cylinder 62 is then extended or retracted, as required, to rotate
the working arm arrangement about the upright axis X such that the
working arm is substantially parallel to the axis B. In this
position, an operator is seated facing towards the working arm
arrangement 40 and has good visibility of the region that requires
excavating. Additionally, if the operation is a linear trenching
operation the working machine can simply be repositioned by
reversing once a portion of the trench is excavated.
[0103] The stabilizer arrangement 24 can be deployed to engage the
ground for added stability. If further stability is required, the
dozer blade arrangement 22 can be extended to engage the ground and
lift the wheels 19a, 19b of the front axle 20a off the ground.
[0104] The hydraulic cylinders 52, 54, 60 can then be used to pivot
the first and second sections of the boom 42 relative to each
other, pivot the dipper 44 relative to the boom 42, and/or pivot
the bucket 58 relative to the dipper, as required to perform an
excavating operation.
[0105] As can be seen in FIG. 1, the configuration of the working
machine 10 enables an operator to have good visibility of the area
being excavated.
Offset Dig Operation
[0106] Referring to FIGS. 5 to 7, an offset mode of excavating is
shown. This type of excavating may be used, for example, if the
working machine 10 is being used to dig a trench near a wall. In
this mode of operation the cab 30 can be rotated so as to be facing
towards an end where the dozer blade 22 is positioned, but
transverse to the axis B so that the operator is facing towards the
trench to be dug. The superstructure is rotated so that the
counterweight 34 is rearward of the cab 30 but offset to one side
and the working arm arrangement 40 is forward of the cab 30 but
offset to one side thereof.
[0107] The hydraulic cylinder 62 is then retracted to rotate the
working arm arrangement 40 so as to extend in the fore-aft
direction. If required, the stabilizer arrangement 24 and
optionally the dozer arrangement 22 are extended for additional
stability. The hydraulic cylinders 50, 52, 54 and 60 are then
operated to move the working arm arrangement 40 to dig the trench.
Further, repositioning after a digging operation may be achieved by
simple reversing of the working machine.
Roadinq Operation
[0108] Referring to FIGS. 8 to 11, if an operator wants to drive
the working machine 10, for example on the road, for a significant
distance (i.e. a "roading" operation) the cab 30 is rotated so that
an operator is facing a direction generally towards the stabilizer
arrangement 24. The superstructure 14 is rotated so that the
counterweight 34 is at the front of the cab and the working arm
arrangement 40 is to the rear of the cab.
[0109] The hydraulic cylinders 50, 52, 54 and 60 are extended to
fold the working arm arrangement 40 into a compact
configuration.
[0110] Positioning the working arm arrangement 40 behind the cab
30, the small height of the counterweight 34 and the position of
the engine within the undercarriage ensures that the operator's
vision during driving is optimized.
[0111] As is evidenced from the described modes of operation, the
working machine of the present invention enables an operator to
perform numerous different operating tasks in a confined space and
with improved visibility.
Variants
[0112] Although the invention has been described above with
reference to one or more preferred embodiments, it will be
appreciated that various changes or modifications may be made
without departing from the scope of the invention as defined in the
appended claims.
[0113] For example, the ground engaging structure of the described
working machine includes wheels, but in alternative embodiments two
endless tracks may be provided.
[0114] The attachment shown connected to the working arm in the
described embodiment is a bucket and the described working
operation is digging, but in alternative embodiments an alternative
attachment may be used and/or the working machine may be used for
an alternative working operation. For example, the attachment may
be a grading or ditching bucket, grapple, a waste and recycling
attachment, a hydraulic breaker, or an earth drill, etc.
[0115] In the presently described embodiment the engine is
positioned between the front and rear axles because this helps to
provide a more compact working machine, but advantages of the
invention can be achieved in alternative embodiments where for
example the prime mover is an electric motor provided to directly
drive each axle or each wheel.
[0116] In the presently described embodiment the engine is
positioned perpendicular to the axis B so as to reduce the
packaging size of the engine and transmission of the present
embodiment, but advantages of the invention can be achieved in
alternative embodiments where the engine may be positioned at an
alternative transverse position, for example between 30 and
70.degree. to axis B measured in a clockwise direction.
[0117] In the presently described embodiment the engine is
positioned such that a longitudinal axis of the pistons is
orientated substantially upright, but in alternative embodiments
the pistons may be alternatively orientated, for example the
pistons may be substantially horizontal. In further alternative
embodiments, the prime mover may not be a diesel engine, for
example the engine may be a petrol engine, further alternatively
the prime mover may not be a reciprocating engine, for example the
engine may be an electric motor powered by one or more batteries or
a fuel cell.
[0118] The arrangement of the fuel tank, hydraulic fluid tank, heat
exchanger, fan and engine of the present invention is advantageous
because of its compact nature, but advantages of the invention can
be achieved in alternative embodiments where these components may
be positioned in alternative locations, for example the fuel tank
and hydraulic fluid tank may not be positioned between the
axles.
[0119] The cab of the presently described embodiment is positioned
substantially centrally to the superstructure which means that an
operator's line of sight is similar on both lateral sides of the
working machine, but in alternative embodiments the cab may be
offset from the center of the superstructure. The cab and
superstructure of the present invention are dimensioned such that
the cab stays within a region defined by the superstructure in all
modes of operation, but in alternative embodiments a portion of the
cab may overhang the superstructure in certain modes of
operation.
[0120] In the described embodiment, the superstructure 14 is
mounted at a central position of the undercarriage 12 which has
been found to be optimal for improved visibility and compactness of
the working machine, but advantages of the invention can be
achieved in alternative embodiments where the superstructure may be
mounted at any suitable position on the undercarriage.
[0121] The counterweight of the presently described embodiment is
curved to accommodate the cab, but in alternative embodiments the
counterweight may be sufficiently spaced from the cab to permit
rotation of the cab and/or the counterweight may be provided as a
discrete plurality of weights.
[0122] The working arm of the present embodiment is a king post
arrangement, but in alternative embodiments the working arm
arrangement may be pivotally mounted to the superstructure in any
other known way.
[0123] The working arm described includes a dipper and a triple
articulated boom, but in alternative embodiments the boom may only
be articulated at the connection to the superstructure and the
dipper. In further alternative embodiments a section of the boom or
the dipper may be telescopic.
[0124] In other embodiments, an alternative transmission
arrangement may be used, such as a conventional gearbox, powershift
gearbox and/or torque converter gearbox. An alternative prime mover
may also be used instead of or in conjunction with an IC engine,
for example an electric motor.
[0125] The working machine may be operated using manual, hydraulic
or electro-hydraulic controls.
[0126] The relative dimensions of the cab, superstructure and
undercarriage of the present invention have been optimized to
further improve the line of sight of an operator, but advantages of
the invention can be achieved in alternative embodiments where any
suitable relative dimensions may be selected.
[0127] In the present embodiment, the wheels on both axles are
steerable (i.e. the working machine is configured for four wheel
steer), but in alternative embodiments only the wheels on one of
the axles may be steerable (i.e. the working machine is configured
for two wheel steer).
[0128] In the present embodiment, the cab is shown in the figures
is a fully enclosed structure with a cab door, but in alternative
embodiments the cab may be an open structure having a roof and
accommodating the control panel and operator seat.
* * * * *